2010-02-11 23:55:29 +00:00
|
|
|
; RUN: llc < %s -march=x86 | grep mov | count 4
|
Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue.
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1028
%reg1030<def> = ADD8rr %reg1028<kill>, %reg1029<kill>, %EFLAGS<imp-def,dead>
In this case, it might not be possible to coalesce the second MOV8rr
instruction if the first one is coalesced. So it would be profitable to
commute it:
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1029
%reg1030<def> = ADD8rr %reg1029<kill>, %reg1028<kill>, %EFLAGS<imp-def,dead>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62954 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-25 03:53:59 +00:00
|
|
|
; rdar://6523745
|
|
|
|
|
|
|
|
@"\01LC" = internal constant [4 x i8] c"%d\0A\00" ; <[4 x i8]*> [#uses=1]
|
|
|
|
|
2010-09-02 03:45:51 +00:00
|
|
|
define i32 @foo() nounwind {
|
Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue.
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1028
%reg1030<def> = ADD8rr %reg1028<kill>, %reg1029<kill>, %EFLAGS<imp-def,dead>
In this case, it might not be possible to coalesce the second MOV8rr
instruction if the first one is coalesced. So it would be profitable to
commute it:
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1029
%reg1030<def> = ADD8rr %reg1029<kill>, %reg1028<kill>, %EFLAGS<imp-def,dead>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62954 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-25 03:53:59 +00:00
|
|
|
bb1.thread:
|
|
|
|
br label %bb1
|
|
|
|
|
|
|
|
bb1: ; preds = %bb1, %bb1.thread
|
|
|
|
%i.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %indvar.next, %bb1 ] ; <i32> [#uses=2]
|
|
|
|
%0 = trunc i32 %i.0.reg2mem.0 to i8 ; <i8> [#uses=1]
|
|
|
|
%1 = sdiv i8 %0, 2 ; <i8> [#uses=1]
|
|
|
|
%2 = sext i8 %1 to i32 ; <i32> [#uses=1]
|
2015-03-13 18:20:45 +00:00
|
|
|
%3 = tail call i32 (i8*, ...)* @printf(i8* getelementptr ([4 x i8], [4 x i8]* @"\01LC", i32 0, i32 0), i32 %2) nounwind ; <i32> [#uses=0]
|
Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue.
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1028
%reg1030<def> = ADD8rr %reg1028<kill>, %reg1029<kill>, %EFLAGS<imp-def,dead>
In this case, it might not be possible to coalesce the second MOV8rr
instruction if the first one is coalesced. So it would be profitable to
commute it:
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1
%reg1029<def> = MOV8rr %reg1028
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>
insert => %reg1030<def> = MOV8rr %reg1029
%reg1030<def> = ADD8rr %reg1029<kill>, %reg1028<kill>, %EFLAGS<imp-def,dead>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62954 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-25 03:53:59 +00:00
|
|
|
%indvar.next = add i32 %i.0.reg2mem.0, 1 ; <i32> [#uses=2]
|
|
|
|
%exitcond = icmp eq i32 %indvar.next, 258 ; <i1> [#uses=1]
|
|
|
|
br i1 %exitcond, label %bb2, label %bb1
|
|
|
|
|
|
|
|
bb2: ; preds = %bb1
|
|
|
|
ret i32 0
|
|
|
|
}
|
|
|
|
|
|
|
|
declare i32 @printf(i8*, ...) nounwind
|